Bug fix for install.sh

Hi folks, I had trouble installing the Haskell Platform 2009.2.0.2 from source on Ubuntu 9.04 with an existing GHC 6.10.4 installation. The problem was that some packages were already installed. The build.sh script was smart enough to avoid building packages that were already installed, but the in

Bug fix for install.sh

Hi folks, I had trouble installing the Haskell Platform 2009.2.0.2 from source on Ubuntu 9.04 with an existing GHC 6.10.4 installation. The problem was that some packages were already installed. The build.sh script was smart enough to avoid building packages that were already installed, but the in